Is it better to initiate treatment with Bupropion (Wellbutrin) extended release (XL) or sustained release (SR)?

From the Guidelines

Wellbutrin XL is generally preferred for most patients starting bupropion therapy due to its once-daily dosing and more consistent blood levels throughout the day, which may reduce side effects like insomnia. The choice between Wellbutrin XL and Wellbutrin SR depends on individual needs, but the XL formulation offers better convenience and potentially improved adherence, which is particularly important when beginning treatment for depression or smoking cessation. Some key points to consider when choosing between Wellbutrin XL and SR include:

• Dosing frequency: Wellbutrin XL is taken once daily (typically 150-300 mg) while Wellbutrin SR requires twice-daily dosing (usually 150 mg twice daily)
• Side effects: XL provides more consistent blood levels throughout the day, which may reduce side effects like insomnia that can occur with the SR formulation's second daily dose
• Flexibility: Wellbutrin SR might be preferable for patients who need more flexible dosing or who experience side effects with the XL version
• Active ingredient: Both formulations contain the same active ingredient (bupropion hydrochloride) and are effective for treating depression and aiding smoking cessation
• Medication delivery: The extended-release technology in the XL version creates a more gradual and sustained medication delivery When starting either formulation, patients typically begin with a lower dose for several days before increasing to the target dose to minimize side effects, as recommended by studies such as 1.

From the FDA Drug Label

1. 4 Switching Patients from WELLBUTRIN Tablets (Bupropion Hydrochloride Tablets) or from WELLBUTRIN SR Sustained-Release Tablets (Bupropion Hydrochloride Sustained-Release Tablets (SR)) When switching patients from WELLBUTRIN tablets (bupropion hydrochloride tablets) to bupropion hydrochloride extended-release tablets (XL) or from WELLBUTRIN SR sustained-release tablets (bupropion hydrochloride sustained-release tablets (SR)) to bupropion hydrochloride extended-release tablets (XL), give the same total daily dose when possible.

The FDA drug label does not provide a direct comparison of starting with Wellbutrin XL versus Wellbutrin SR. However, it does provide guidance on switching from one formulation to another, suggesting that the same total daily dose be used when possible 2.

• The label does not specify which formulation is better to start with.
• It emphasizes the importance of gradual dose increases to minimize the risk of seizure.
• The decision to start with Wellbutrin XL or Wellbutrin SR should be based on individual patient needs and clinical judgment.
• Key considerations include the patient's historical pattern of depressive episodes, the presence of any hepatic or renal impairment, and the potential for drug interactions.

From the Research

Comparison of Wellbutrin XL and Wellbutrin SR

• Both Wellbutrin XL and Wellbutrin SR are formulations of bupropion, used in the management of major depressive disorder and smoking cessation 3.
• Wellbutrin SR is administered twice daily, while Wellbutrin XL is administered once daily 3.
• The efficacy of bupropion SR in the treatment of major depressive disorder has been established, with a generally similar tolerability profile to some SSRIs, but with less somnolence and sexual dysfunction 3.
• Bupropion XL has also demonstrated efficacy in the treatment of major depressive disorder, with a similar tolerability profile to escitalopram and venlafaxine XR, but with less sexual dysfunction 3.

Adverse Events

• Common adverse events associated with bupropion SR include insomnia, headache, dry mouth, nausea, and anxiety 4.
• Bupropion XL has a similar adverse event profile to bupropion SR, with common events including nausea, dry mouth, headache, insomnia, dizziness, anxiety, tremor, and constipation 5.
• Infrequent but clinically important adverse reactions to bupropion include seizures and hypersensitivity reactions, with an incidence of approximately 0.1% for each event 4.

Choosing Between Wellbutrin XL and Wellbutrin SR

• The choice between Wellbutrin XL and Wellbutrin SR may depend on individual patient factors, such as dosing preferences and adverse event profiles 3.
• Bupropion SR has been shown to be effective and generally well tolerated in the treatment of major depressive disorder, with a low discontinuation rate due to adverse events 4.
• Bupropion XL has also demonstrated efficacy and tolerability in the treatment of major depressive disorder, with the advantage of once-daily dosing 3.